The present disclosure relates to respiratory therapy devices and methods for administering breathing-relating treatments (e.g., oscillatory, continuous, etc.) to a patient. More particularly, it relates to respiratory therapy devices capable of creating oscillatory respiratory pressure pulses in response to the patient's expiratory airflow alone, or when connected to a source of positive pressure fluid (e.g., air, oxygen, etc.), or both. One or more additional therapies (e.g., continuous positive airway pressure, continuous positive expiratory pressure, delivery of aerosolized medication, etc.) are optionally available in some embodiments.
A wide variety of respiratory therapy devices are currently available for assisting, treating, or improving a patient's respiratory health. For example, positive airway pressure (PAP) has long been recognized to be an effective tool in promoting bronchial hygiene by facilitating improved oxygenation, increased lung volumes, and reduced venous return in patients with congestive heart failure. More recently, positive airway pressure has been recognized as useful in promoting mobilization and clearance of secretions (e.g., mucous) from a patient's lungs. In this regard, expiratory positive airway pressure (EPAP) in the form of high frequency oscillation (HFO) of the patient's air column is a recognized technique that facilitates secretion removal. In general terms, HFO reduces the viscosity of sputum in vitro, which in turn has a positive effect on clearance induced by an in vitro simulated cough. In this regard, HFO can be delivered or created via a force applied to the patient's chest wall (i.e., chest physical therapy (CPT), such as an electrically driven pad that vibrates against the patient's chest), or by applying forces directly to the patient's airway (i.e., breathing treatment, such as high frequency airway oscillation). Many patients and caregivers prefer the breathing treatment approach as it is less obtrusive and can more easily be administered. To this end, PAP bronchial hygiene techniques have emerged as an effective alternative to CPT for expanding the lungs and mobilizing secretions.
In the context of high frequency oscillatory breathing treatments, various devices are available. In general terms, respiratory therapy devices typically include one or more tubular bodies through which a patient breaths, with the tubular body or bodies creating or defining a patient breathing circuit. With this in mind, the oscillatory airflow effect can be created by periodically generating a pressure or positive airflow in the patient breathing circuit during one or both of an inspiratory phase or expiratory phase of the patient's breathing cycle. For example, a positive expiratory pressure (PEP) can work “against” the patient's breath during the expiratory phase of breathing. The pressure can be generated by creating a periodic (or in some instances continuous) resistance or restriction in the patient breathing circuit to expiratory airflow from the patient, or by introducing a forced fluid flow (from a positive pressure gas source) into the patient's breathing circuit in a direction opposite of the patient's exhaled air. With the airflow resistance approach, a separate, positive pressure gas source is not required. More particularly, many oscillatory positive expiratory pressure (“oscillatory PEP”) therapy devices utilize the patient's breath alone to drive an oscillatory fluid flow restriction, and thus can be referred to as “passive” devices (in contrast to an “active” respiratory therapy device that relies on a separate source of positive pressure gas as described below). Passive oscillatory PEP devices are self-administering and portable.
The Flutter® mucus clearance device (available from Axcan Scandipharm Inc., of Birmingham, Ala.), is one example of an available passive, oscillatory PEP therapy device. In general terms, the Flutter device is pipe-shaped, with a steel ball in a “bowl” portion of a housing that is loosely covered by a perforated cap. The ball is situated within an airway path defined by the device's housing; when the patient exhales into the housing, then, the ball temporarily obstructs airflow, thus creating an expiratory positive airway pressure. The bowl within which the ball is located allows the ball to repeatedly move (e.g., roll and/or bounce) or flutter to create an oscillatory or vibrational resistance to the exhaled airflow. While relatively inexpensive and viable, the Flutter device is fairly sensitive, requiring the patient to maintain the device at a particular angle to achieve a consistent PEP effect. Other passive oscillatory positive expiratory pressure devices, such as the Acapella® vibratory PEP therapy system (available from Smiths Medical of London, England) and the Quake® secretion clearance therapy device (available from Thayer Medical Corp., of Tucson, Ariz.) are known alternatives to the Flutter device, and purport to be less sensitive to the position in which the patient holds the device during use. While these and other portable oscillatory PEP therapy devices are viable, opportunities for improvement remain, and patients continue to desire more uniform oscillatory PEP results.
As an alternative to the passive oscillatory PEP devices described above, continuous high frequency oscillatory (CHFO) treatment systems are also available. In general terms, the CHFO system includes a hand-held device establishing a patient breathing circuit to which a source of positive pressure gas (e.g., air, oxygen, etc.), is fluidly connected. The pressure source and/or the device further include appropriate mechanisms (e.g., control valves provided as part of a driver unit apart from the hand-held device) that effectuate intermittent flow of gas into the patient breathing circuit, and thus percussive ventilation of the patient's lungs. With this approach, the patient breathes through a mouthpiece that delivers high-flow, “mini-bursts” of gas. During these percussive bursts, a continuous airway pressure above ambient is maintained while the pulsatile percussive airflow periodically increases airway pressure. Each percussive cycle can be programmed by the patient or caregiver with certain systems, and can be used throughout both inspiratory and expiratory phases of the breathing cycle.
Examples of CHFO devices include the IPV® ventilator device (from PercussionAire Corp., of Sandpoint, Id.) and a PercussiveNeb™ system (from Vortran Medical Technology 1, Inc., of Sacramento, Calif.). These and other similar “active” systems are readily capable of providing not only CHFO treatments, but also other positive airflow modes of operation (e.g., continuous positive airway pressure (CPAP)). However, a positive pressure source is required, such that available active respiratory therapy systems are not readily portable, and are relatively expensive (especially as compared to the passive oscillatory PEP devices described above). Oftentimes, then, active respiratory treatment systems are only available at the caregiver's facility, and the patient is unable to continue the respiratory therapy at home. Instead, a separate device, such as a portable, passive oscillatory PEP device as described above must also be provided. Further, the hand-held portion of some conventional active respiratory therapy systems must be connected to an appropriate driver unit that in turn is programmed to effectuate the desired fluid flow to the patient (e.g., CHFO, CPAP, etc.). That is to say, the hand-held portion of some active systems is not self-operating, but instead relies on the driver unit for applications. Any efforts to address these and other limitations of available active respiratory therapy devices would be well-received. This limitation represents a significant drawback.
In light of the above, a need exists for respiratory devices capable of providing oscillatory PEP therapy utilizing the patient's breath alone, as well as CHFO therapy (and optionally other therapies such as CPAP) when connected to a positive pressure source. In addition, improved passive oscillatory PEP or active respiratory therapy devices are also needed.